The unexpected arrival of Mayor Wilson Loewen at Oz spurs an ironic turn involving Schillinger and Beecher. Meanwhile, Dr. Nathan discovers why solitary inmates are getting sick; a new business plan within Oz inspires Redding; Schibetta looks to puts a curse on the O'Reily family; and some Death Row prisoners get a bang out of a magazine photo shoot.

Schillinger has a disappointing visit with his "hero", Mayor Loewen. Glynn has to face up to the truth when Oz loses its first prisoner to toxic poisoning. Down in solitary, Officer Brass gets some quality one-on-one time with Morales. Cyril undergoes a round of unusual therapy, and Said gets more than he bargained for in leading the Muslims into a new business venture.

Glynn receives some good and bad news on the toxic-poisoning case. Meanwhile, Rebadow's relationship with Stella hits a snag; Keller and Beecher work out a mutually beneficial arrangement; Poet and Redding nearly come to blows; Hoyt is transferred from Death Row; and Robson finally gets some redemption.

Idzik faces his enemies; the intrigues behind the Loewen case get more complicated; changes are made in the hospital; the Muslims run into business trouble; Rebadow and Stella get closer; and the inmates rally to support the O'Reilys.

Oz is in upheaval following the return of Martin Querns. Meanwhile, Howell and Robson each receive troubling news, Mukada answers an unsolved mystery, and the O'Reilys struggle to make amends. Finally, the prison production of 'Macbeth' ends with a staggering final act.